1. Field of the Invention
The present invention relates to dipping type wafer treatment apparatus for treating surfaces of laminated wafers such as semiconductor substrates or liquid crystal glass substrates (hereinafter simply referred to as a wafer), and particularly to a wafer treatment apparatus capable of efficiently exhausting mist produced from a treatment solution.
2. Description of the Related Art
Conventional wafer treatment apparatus of this kind is disclosed in FIG. 1 of Japanese Patent Laying-Open No. 2-238022 (Title of the Invention "Semiconductor Treatment Apparatus") shown in FIG. 1. As shown in FIG. 1, a conventional apparatus 101 includes a surface treatment chamber 102A, a plurality of surface treatment baths 103 provided in a series in the surface treatment chamber 102A, and a conveyor robot 110 for sequentially conveying a carrier 104 in which a wafer W is accommodated to dip it into each treatment bath 103 for performing different kinds of surface treatments. A sidewall 114 defines surface treatment chamber 102A and a side chamber 102B around surface treatment baths 103 in four directions. An air outlet 122 is formed in a rear sidewall of surface treatment chamber 102A and a forced exhaust duct 123 is connected thereto. A clean air flow F is supplied from top to bottom in surface treatment chamber 102A and treatment solution mist produced from surface treatment bath 103 is forced out together with the downflow F of clean air. Apparatus 101 is installed on a floor beam 140 of the waffle slab structure.
In the above-described conventional example, as shown in FIG. 1, air outlet 122 is formed in the rear sidewall of surface treatment chamber 102A, and forced exhaust duct 123 is connected thereto. It causes such problems as follows.
As it is near the air outlet 122, the exhaustion effect on the rear side of surface treatment bath 103 is strong. However, as it is spaced away from air outlet 122, the exhaustion effect is weak on the front side of surface treatment bath 103, resulting in a difficulty in smoothly exhausting the treatment solution mist.
Another problem is as follows. This kind of apparatus is generally installed on floor beam 140 with the waffle slab structure as shown in FIG. 1. In some installing places, forced exhaust duct 123 interferes with floor beam 140. Accordingly, as shown by the phantom line, forced exhaust duct 123 must be connected by a tube in a manner largely drawn out to the rear side of wafer treatment apparatus 101. Therefore, for providing the conventional apparatus, it is necessary to re-design the pipe arrangement corresponding to an installation place.